The purpose of this study is to develop the monitoring system for plant water content. In order to increase the number of plants that take carbon dioxide, which is said to be the cause of global warming, we will develop a monitoring system for managing the Water Content of plants. We developed a noncontact measurement system using radio waves. It did not work on the 315 MHz radio module. However, it was able to measure by using the 2.4 GHz radio module. As a result of the experiment, we could measure change of water content.